0chase@ridetech

C5/C6 Corvette Delrin Bushing Upgrade


If you are looking to get more performance and handling capability out of your C5/C6 Corvette Ridetech has you covered!

With very few upgrades you can turn a C5 or C6 into a highly competitive track animal. One modification that should be on every corvette owner's list is getting rid of the factory spongy control arm bushings.
Today's Corvette drivers demand maximum performance without compromise and RideTech’s new direct fit bushing system will leave you with unrivaled control. Our “Direct Fit” technology makes upgrading your bushings a “DIY” breeze thanks to precise machining and included hardware. Now you can take those curves with confidence.

We have done a significant amount of testing on our track and road cars and have seen better lap times and more predictable handling. The delrin takes out the deflection that plagues the rubber bushings.

FEATURES

• Delrin bushing design eliminates control arm shift common with factory bushings.
• Reduction in deflection creates consistent and predictable handling.
• Trunion design captures bushings from both sides increasing strength and rigidity in
upper arms.
• Designed to resist binding at extreme alignment settings.
• Includes new trunions CNC machined from 4130 chromoly.
• No modifications necessary.
• Replaces all 16 control arm bushings.
• Split bushing design for easy installation.


Part# Price
1997-2013 C5/C6 11519500 $750
2006-2013 C6 Z06 11519501 $900






check them out here:
http://www.ridetech.com/store/c5-cor...shing-kit.html

mgarfias

And how are you dealing with the axial misalignment in the arms?

fatbillybob

Specifically the rear lower IIRC yes?

mgarfias

Well... My C5Z had washers under the front uppers from the factory, so those had misalignment. The lowers from the factory were set to have camber and caster, so that the lower front arm has misalignment. The rear lowers are nothing but. The rear uppers on the C5Z and steel C6s is the only place that delrin can really go assuming all else is stock.

My C5Z as it sits now, has camber blocks set square on the lower front arms, which means I can put delrin there. Some of you can, some of you can't. Phoenix gets around this by drilling their delrin bushings specifically for the car, that is, the axis of the bolt hole isn't coaxial with the bore of the arm that holds the bushing. I don't see that here.

fatbillybob

Humm.... I don't remember that at all on my C5Z. In around 2012 SCCA CRB allowed us delrin or spherical. spherical was huge money and no one yet made delrin. So I cut my own on my lathe and only remember the lower rear bushing to be at angle making things difficult. I can't even remember the solution.

0chase@ridetech

The ID of the bushing has a slight taper and the outside of the bushing is conical. I should have a drawing soon that will better represent this.

firebirdfan

Really? That's rather interesting.

What kind of angle are you talking here? There's quite a bit of "misalignment" that can be added between the camber eccentrics on the front, though I have a feeling most don't have them at the extremes.

Is there any concern about the play in the "open" at the opposite side of the cone in the arm where the bushing isn't contacting? Seems like if there was any sort of slippage or wear, they would start to wiggle and be noisy/wear very quickly.

Are these streetable? Not so much in the comfort sense, but in terms of reliability? I don't want to do something like this and need to replace them every 2 years because I put 10k miles a year on the car (if not more).

I know my car has both the front eccentrics turned for max camber. It put my camber at -2* and my caster at about 6.5. I don't have any complaints with the setup yet. Though, my rear does leave a LOT to be desired due to the rear subframe being ALL the way to the right side of the car. The left rear maxed out at -0.3*.

froggy47

I sort of get the issue, but could someone explain it using a common sense example or a drawing?



Also how does the vendor "get around" the GM "problem" that the bushing "holes" are many different sizes - due to the less than precise spec needed for rubber bushings?

fatbillybob

Froggy,

There is no prob I can remember when I cut my own bushings. I used all oem parts except xpfadt dogbones for the front deleting their poly bushing for my lathe cut delrin. There is no issue with the bushings on the cam adjusters since whole bushing pack moves laterally in the subass slots. So what ridetech is showing is just fine. The only issue I can remember is the rear lower CA rear area is mildly off angle and you have to be creative on how you cut that. In a few years of racing I still have not needed to replace or refresh mine. Delrin is delrin regardless of who cuts it. It therefore is very durable and long lasting.

firebirdfan

I don't think the bushing diameters vary that much, and even if they did, it may not be an issue with this particular design.

People have been using delrin bushings for a LONG time in these cars. I've yet to see anyone put out ACTUAL numbers for how out of round the control arms actually are. If I decide to do this to my car, I'm taking measurements before and after the rubber has been removed.

Ridetech has posted a picture below explaining the function.

On the design, I drew this up really quickly (sub-30 minutes) to explain how I think they're accomplishing it. Again, this is initial speculation since we haven't seen a drawing or anything from them yet.

There's 2 situations:
1) An inward taper (draft) on the OD of the bushing and an outward taper on the ID.
2) An outward taper on the OD of the bushing and an inward taper on the ID.

Here's situation 1, with the bushings "aligned" via the center axis:

*PICTURE REMOVED*


Here's situation 2, with the bushings "aligned" via the center axis:
*PICTURE REMOVED*

My concern with this is how it acts when the control arm and trunnion aren't concentric. The bushings are design with the taper (draft) to handle the misalignment. This means that there are point loads on the bushings where they stop misaligning.

Here's situation 1 with the points of contact:

*PICTURE REMOVED*


Here's situation 2 with the points of contact:

*PICTURE REMOVED*

I'm thinking Ridetech is using method 2 on their bushings. It seems to fit better. They may also have a "curved" draft on the OD instead of just a straight taper. I used the straight taper in my model just for explanation.

Again, this is just speculation on my part. Seems like it would work and would handle misalignment, but I'm concerned about the "point" loads on the bushings at the edges. That's what I'm concerned about wearing out.

Ridetech knows their stuff. I'm sure they've built a fine product. I've seen their other work and every bit of it is fantastic.

I'm just curious how it fits together. The price seems spot on and is very budget friendly. I just like certain things explained before I spend $750. I want to make sure this thing will last on the street (yes, I hate rubber bushings that much).

froggy47

That's good, just to be clear, I am not talking "out of round" I am saying the CA holes are different sizes by a few thou from car to car (this according to A Pfadt among others - I spoke with him a few ago when I bought his poly kit).

I am saying if you have arms that ran on the small side of "QA acceptable" can you still shove the delrin in the hole by "hand"?

If you press it in what happens to the dimension of the inner hole that the dog bone passes thru?

Does it hold shape, because it's delrin?

skxf430

Fatbilly,

Do you get any noise coming from the Delrin?

0chase@ridetech

Here is a cross section of the control arm bushing, control arm, and frame mount.

firebirdfan

Interesting. Thanks for the picture.

Any concern with the center points of the delrin having all the force/wear on them?

Are these streetable? Will they hold up in all weather for approx 10k miles a year of street driving?

froggy47

Do they slide in, press in, need to be fitted???



If hand fitted, how?

fatbillybob

These 2 issues might be related?? Froggy is right. On my C5Z each control arm is a few thou different. All streetcars I have worked with are like that because they are designed for the impreciseness of rubber. I hand fitted each bushing so that there is mild hand friction of bushing to CA. This resulted in a very precise fit. A thousandth off can be felt by hand! My fitting near snug resulted in CA's that droop on their own weight with no perceptible bushing slop when shook by hand. I want my CA's to act like on spherical bearings. I have zero noise on my racecar but it is a racecar. I also have zero noise on a Ferrari streetcar on delrin. Delrin is self lubricating and it does not squeak like polyU. Close tolerances make for a "no clunk" suspension. At what point do you get clunk? I do not know. This is just not an issue with custom cut delrin. Back to Froggy's point I would be more worried about too loose a fit vs. too tight. You see, Delrin is easy to machine but I would not want to try and hand sand off a thousandth to get it to fit precisely. That would be hard work but can be done. This is a very time consuming job even with tools. I have found delrin very hard and very dimensionally stable. You would need quite a tight fit on a bushing OD to crush it enough to effect the ID if in delrin. I think you would have a harder time getting such a bushing into the CA even with a press. When you work with delrin think soft aluminum. Delrin has a look and feel more like aluminum than rubber or polyU. Friction like that would not allow your suspension to move so you can't allow that anyway.

marolf101x

I figured I should jump in here and give a little more background to the story. I apologize up front for the length of this post.
Until the 1st of this year I was the Director of Engineering for Ridetech.

The bushings you see here are based on a design we did around 5 years ago for our aftermarket control arms. We wanted to use Delrin, but also wanted to injection mold them to keep costs down.
You can see them in an upper control arm here:


***Side note. . .Delrin by itself is not that expensive, but when you add Teflon (PTFE) the price increases. Typically most people machine their bushings from extruded rod as Delrin is easily machined and you don’t incur injection mold tooling costs. The problem is that the extruded Delrin with 13% PTFE is 10X the cost of the same material in pellet form as used for injection molding. So most of the time you see people make white Delrin bushings. This is typically Delrin without Teflon. Back to the story. . .***

To injection mold them required draft in the bushings so they would release from the mold.
What we ended up doing was having the OD press fit into our control arm bushings sleeves. This provided enough material engagement that the bushing could handle the load without premature wear or damage. This press fit and the mating surface between the bushing “ledge” and the side of the control arm sleeve keeps them from “rocking” or moving about.

We spent a considerable amount of time testing and verifying these would work. For example I built a test fixture that ran 2 bushings simultaneously. . .one in an agitated “mud bath” and one in open air as a control. The bushings were cycled just as they would be in a control arm continuously for weeks with no lubrication (as it has Teflon lubrication is not required). They were then measured and compared to an unused bushing to see just how much wear was incurred in the “dry” and the “dirty” environment.
We also did a lot of compression testing. . .for example, putting them in a press to find the deflection at whatever force. As well as thousands of actual road miles on our house cars.

Since releasing these to the public roughly 5 years ago we’ve not had a single complaint, failure, or warranty claim. Our house cars have tens of thousands of miles on them now from daily driving (we actually do take them to lunch all the time), to road trips (Power Tour, driving to all the shows and competitive events) and competitive events (SCCA autocross, Good Guys autocross, Optima Ultimate Street Car Events, etc).
We once had a header on our 66 Chevelle that literally wrapped around one of the upper control arm sleeves (think big dent in the header with the control arm sitting in the dent). I let this go for a while just to see how the bushings handled the extreme heat. Though the bushing mostly melted it did retain enough shape and surface area that the control arm never moved or made a sound. Eventually I replaced it (and changed the headers). But to look at that bushing you would have sworn it wouldn’t work.

The bushings for the Corvette are currently CNC machined from extruded Delrin with PTFE. However, they were designed to be injection molded, and may someday go that route. We just wanted to get a good product to the market as quickly as possible.
They are a press fit on the OD to overcome the machining tolerances of the control arms, though you can easily do this at home with a vice (you’ll need one to remove the OE bushings as well). As you can tell the ID is also tapered, which provides enough surface area to handle the load while, in conjunction with the outside “dome”, allows the control arm to be adjusted to the maximum limits inside the OE aluminum subframe without binding.

These are currently on our black C5Z06 and our silver C5 base car as well as a good number of outside third party vehicles. . .so we’ve been running them quite a while already in a number of vehicles.

froggy47

When you set the OD's of the bushings (for Corvette) what dimension did you use? Off a house car, customer car, GM design spec?

If I buy a set & they don't press in "readily" what do I do? I have installed poly's with a press/vice so I know how.

marolf101x

"When you set the OD's of the bushings (for Corvette) what dimension did you use? Off a house car, customer car, GM design spec?"
-House cars, customer cars, GM CAD models and GM prints

If I buy a set & they don't press in "readily" what do I do? I have installed poly's with a press/vice so I know how.
-push harder

We have no indication that there will be any issues installing these. All that we have done in-house, and all done outside have had no issues (it's only a few thousands press fit, not a quarter inch).
That being said there will always be something that pops up. All I can tell you at this point is that we will do whatever it takes to get it right in the shortest possible time frame.

froggy47

Fair enough, thanks.